1PV6

Crystal structure of lactose permease


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å
  • R-Value Free: 0.337 
  • R-Value Work: 0.294 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure and mechanism of the lactose permease of Escherichia coli

Abramson, J.Smirnova, I.Kasho, V.Verner, G.Kaback, H.R.Iwata, S.

(2003) SCIENCE 301: 610-615

  • DOI: 10.1126/science.1088196
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Membrane transport proteins that transduce free energy stored in electrochemical ion gradients into a concentration gradient are a major class of membrane proteins. We report the crystal structure at 3.5 angstroms of the Escherichia coli lactose perm ...

    Membrane transport proteins that transduce free energy stored in electrochemical ion gradients into a concentration gradient are a major class of membrane proteins. We report the crystal structure at 3.5 angstroms of the Escherichia coli lactose permease, an intensively studied member of the major facilitator superfamily of transporters. The molecule is composed of N- and C-terminal domains, each with six transmembrane helices, symmetrically positioned within the permease. A large internal hydrophilic cavity open to the cytoplasmic side represents the inward-facing conformation of the transporter. The structure with a bound lactose homolog, beta-D-galactopyranosyl-1-thio-beta-D-galactopyranoside, reveals the sugar-binding site in the cavity, and residues that play major roles in substrate recognition and proton translocation are identified. We propose a possible mechanism for lactose/proton symport (co-transport) consistent with both the structure and a large body of experimental data.


    Organizational Affiliation

    Department of Biological Sciences, Imperial College London, London SW7 2AZ, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Lactose permease
A, B
417Escherichia coli (strain K12)Mutation(s): 1 
Gene Names: lacY
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: ALPHA-HELICAL
Sub Group: 
Major Facilitator Superfamily (MFS) Transporters
Protein: 
LacY Lactose Permease Transporter (C154G mutant)
Find proteins for P02920 (Escherichia coli (strain K12))
Go to UniProtKB:  P02920
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.5 Å
  • R-Value Free: 0.337 
  • R-Value Work: 0.294 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 101.351α = 90.00
b = 125.845β = 90.00
c = 188.118γ = 90.00
Software Package:
Software NamePurpose
SHARPphasing
DENZOdata reduction
SCALEPACKdata scaling
CNSrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-08-12
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance